Manually-operated press



Feb. 14, 1928.

' 1,659,157 T. c. PROUTY.

MANUALLY OPERATED PRESS Filed March 25, 1926 2 Sheets-Sheet J fi ybvrz IV/ k 0 a YINVENTOR.

A TTORNEYI Feb. 14, 1928.

T. C. PRQUTY MANUALLY OPERATED PRESS Filed March 25. 1926 2 Sheets-Sheet73 IN V EN TOR. W

J i U 4%.. 9% l5 7 g? 0 A TTORNEY fi l Patented Felon l t, lgfiu an ilTHEODORE C. PROUTY, 0F HERMGfi-A BEACH, CALIFORNIA, ASSIGNOB TO AMERICANENCAUSTIC TILING- COMPANY, LTD, 013 NEW YORK, N. Y., A CORPORATION OFNEW YORK.

MANUALLY-OPERATED PRESS.

The object of the invention described and claimed herein is theprovision of means whereby the movable member of the hydraulic press maybe moved through that part of its poweiustroke in which there 1s noresistance from the material or ob1ect 1n the press and through all orsubstantially all of the return stroke by the direct application ofmechanical as distinguished from hydraulic torce thereto, force beingtransmitted to the head through the liquid confined between the smalland large plungers only during the relatively small part of the powerstroke during which the movement of the pressure member is opposed bythe resistance of the material or object in the press. In the operationof any press a large part of the movement is that necessary to separatethe dies sutliciently to permit convenient and rapid insertion of thework in and its removal from the press. The only part of the movement ofthe press requiring the exertion of great force is that which takesplace on the power stroke after contact is established between the workand the movable die. During all the remainder of the movement the onlyforce necessary is that required to overcome the frictional and otherinternal resistance of the mechanism. In a hydraulic press consistingsimply of small and large cylinders with their plungcrs the entiremovement of the press is effected by the expulsion of liquid from thesmall into the large cylinders, thus slowing down the idle part of themovement where little force is required to an extent that greatlyrestricts the number of pressing operations that can be performed in agiven time. Specifically the object of the invention described herein isto effect all of the movement of the press rapidly and with theexpenditure of little power with the exception of the relatively briefinterval when pres sure is being exerted on the material or ob ject inthe press. The operation of a hydraulic press may be speeded up by theuse of a high pressure accumulator for the pressure fluid but thismethod is wasteful inasmuch as it involves the use of the high pressurefluid throughout the entire extent of both the power and returnmovement, whereas high pressure is necessary only during the shortperiod during which the press is acting on the work. The use ot'a lowpressure accumulator for the idle part of the movement and a. highpressure accumulator tor the interval during which the actual work isbeing performed obviates the excessive waste incident to the method lastmentioned but increases the con'iplexity of the mechanism by reason ofthe necessity of having two accumulators together with means for keepingthem properly charged and means for operating the valves connecting theaccumulators with the power cylinders. By the invention herein describedand claimed the movement of the press is etl'ected rapidly and withoutgreat expenditure of power except during the time when pressure is beingexerted on the work, and it is only during this last named briefinterval that the press functions strictly as a hydraulic press.

In the drawings- Figure 1 is a perspective view of a press embodying theinvention, and adapted for use in the dry-mold ceramic process, parts ofthe structure being broken away to show the interior construction.

Figure 2 is a detached view of a slide or wiper used for filling themold with the powdered mixture which the press illustrated is arrangedto compress in a mold.

Figure 3 is a view of the hand-wheel by which the press is operated,this part being omitted from Figure 1 in order not to obstruct the viewof other parts of the mechanism.

Figure 4 is a detached slightly enlarged view of a rack-bar which isengaged by a pinion on the shaft of the hand Wheel.

Figure 5 is an enlarged view of the small plunger, i. e., the upper onejust beneath the rack-bar.

Figure 6 is a detail View of the upper part of the casing and ot africtionally operated valve and valve rod.

tltl

Figure 7 is a detail view of the large plunger and certain connected andco-operating parts.

Figure 8 is. a. perspective view of a modified form of the press.

Figure 9 is a detail view of a modified form of valve to be used in thestructure shown in Figure 8.

In the press illustrated in Figures 1 to 7 rotation of the handwheel 1.which together with pinion 16 is fixed to shaft 2, impart-s sleeve 8 andth movement to rack-bar 3. The lower end of rack-bar 3 is reduced indiameter and tapped at 17, to receive a screw-threaded stem on the upperend of bar 6. The ends of rackbar 3 and bar 6 are brought together in acentral opening in plunger 5 and screwed together to clamp the plungerbetween opposing flanges on members 3 and 6, thus making a single rigidmember of the rackbar 3, plunger 5, and bar 6. .Plunger 5 0perates inthe smaller part 13 of the cylinder of the press. Operating in thelarger part 14 ofthe cylinder is the large plunger 7.

Plunger -7 is provided'with a central aperture 20. Surrounding aperture20 and screw-threaded intothe lower side of plunger 7 is a sleeve 8which is closed at the bottom end where the pressure head 10 of thepress is fixed to it. Within the sleeve 8 is a helical spring 9, thelower end of which abuts against the closed lower end of the e upper,end against a shoulder 19 formed on the rod 6. The rod 6 pro jectsdownwardly into the sleeve 8 part of the length thereof, leaving space,however, between the lower end of rod 6 and the bottom of sleeve 8 topermit downward movement of the rod relative to the sleeve of an extentsuflicient for the purpose hereinafter described. The initial tension ofspring 9 is sufficient to transmit from rod 6 to sleeve 8 and attachedpressure head 10 and plunger 7 the force necessary to move the pressurehead 10 before the die 11 contacts with the object or material in thepress, and hence during this part of the movement the spring 9 is notcompressed.

The oil or other liquid through which the pressure" is transmitted whenthe press is functioning hydraulically is supplied from the reservoir 22which is in free communicatlon with the cylindrical casing 21. Anopening 23 extending through the plunger 5 establishes communicationfrom the casing.

21 to the space between pl'ungers 5 and 7 in the large and smallcylinders 13. 14. Communication through the opening 23 is controlled bya valve 24, the stem 25 of which extends upwardly passing freely througha groove in the side of rack-bar 3 opposite the teeth thereon. The upperend of valve rod 25 passes through a sleeve 26 which projects upwardlyfrom the casing spring friction member 28 is fixed to stem 25. Thisfriction member may conveniently consist of leaf springs carried by atubular member adjustably secured on stem 25. A shoulder 29 (shown indotted lines in Figure 5) projecting'from rod 6 just below plunger 5limits the downward movement of valve 24 relative to the plunger.

The movement of valve 24 relative to plung-' er 5 is thus confined tothe distance between the position of the valve when seated and itsposition when in contact with shoulder 29.

Assuming that the plungers are at their upward limit of movement asshown in Figure 1, that the valve 24 is open, i. e. lowered relative toplunger 5, and that oil or other liquid fills the space between theplungers ,5 and 7 and the casing 25 and reservoir 22, then rotation ofthe hand-wheel in clockwise direction will move rack-bar 3 downward. andwith it plunger 5 and rod 6, parts 3, 5, and 6 being, as above stated,rigidly connected together. At this time the die 11 is free of theobject or material in the press, its uppermost position beingsufliciently high to afford ample clearance for the convenient insertionof the work in the press and its removal therefrom. The first part ofthe downward movement of the movable parts of the press is, therefore,opposed only by the friction and other resistance of the mechanism, andthe downward movement of rod 6 is transmitted through shoulder 19, andspring 9 to the bottom of sleeve 8 which is connected to and in elfect apart of plunger 7, this action taking place without compression ofspring 9, owing to its initial tension being sufficiently high to resistthe force transmitted through it in this part of the operation of thepress. The downward movement of the two plungers just described has theeffect of increasing the volume of the space between the plungers withinthe cylinders, and, valve 24 being at this time open, oil flows throughthe opening 23 in plunger 5 thus filling the increased space betweenlungers 5 and 7. The friction member 28 is adjustable longitudinally ofrod 25 and is so set that at the time, or just before the time, when thedie 11 contacts with the object in the press the friction member entersthe sleeve 26, whereupon its frictional engagement with the insidesurface of the sleeve arrests the downward movement of valve 24.Normally gravity causes the valve 24 with its stem 25 to fall to itslowermost position, in which position the valve rests upon the shoulder24, the relation of these parts being shown in Figure 5, leaving theopening 23 unobstructed. The downward movement of valve24 being arrestedand that of plunger 5 continuing the valve seats in openin 23 thusconfining the oil in the cylinders lietween plungers 5 and 7. Aftervalve 24 is seated further downward movement of plunger 5 carries thevalve with it, this further movement of the valve taking place againstthe frictional resistance between friction member 28 and the inside ofsleeve 26. Upon the closing of valve 24 the mechanism begins to functionas ahydraulic press, continued rotation of the hand-wheel and downwardmovement of plunger 5 forcing oil from the small cylinder 13 into thelarge cylinder 14 and imparting'movement to the large plunger 7inversely proportionate to the cross-sectional areas of the two ill)cylinders. In this part of the movement the travel of the small plunger5 is greater than that of the large plunger, this difierential movementcausing and being permitted by compression of spring 9 in sleeve 8. Themovement of plunger 5 after valve 24 is closed as above described issutlicient to perform the necessary operation upon the object in thepress, and this movement after the closing of valve 24 is permitted bycompression of spring 9.

When the rotation of the hand-wheel l is reversed to raise the die 11the first effect of the upward movement of plunger 5 is to open valve24, the opening of the valve being caused by the fact that the frictionbetween member 28 on stem 25 and the inside of sleeve 26 holds the valve24 stationary while the plunger 5 is moving upwardly. After plunger 5has moved a short distance the shoulder 29 shown in Figure 5, contactswith valve 24 and carries it upward but leaving the valve open. A weight27 is slidably mounted on valve stem 25 above friction member 28. Incase the weight of valve 24 and its stem 25 is not sufficient toreliably hold the valve down in its open position after member 28 hasrisen above sleeve 26 the added weight of member 27, which is carried bythe valve stem 25 when member 28 rises above the top of sleeve 26, willbe suflicient to prevent valve 24 from being closed by the upward rushof oil through opening 23 During the first part of the upward movementof plunger 5 the spring 9 expands until shoulder 19 is stopped byContact with the under side of plunger 7, and during this intervalsubstantially no movement is communicated to plunger 7. This firstupward movement of plunger 5, independently of plunger 7 increases thevolume of the space between the plungers thereby causing oil to be drawnthrough the open valve 24 from the casing 21 into the space between theplungers. After the independent movement of plunger 5 has been arrestedby contact of shoulder 19 with the under side of plunger 7 the furtherupward movement of plunger 5 carries plunger 7 with it. Thissimultaneous and equal movement of plungers 5 and 7 causes a decrease ofthe space between the plungers and valve 24 still being open oil flowsthrough opening 25 from the space between the plungers upwards intocasing 21, this flow being the reverse of that just preceding whenplunger 5 was moving upward- 1y independent of plunger 7.. When plunger5 has been raised to its uppermost position, the position shown inFigure 1, the valve 24 is still open and all of the parts are inposition for the beginning of the cycle of operations above described.

In the form of the press above described the time at which the pressbegins to function hydraulically is governed by the position of thefriction member 28, and to have the hydraulic action begin at the timethe die contacts with the object in the press it is necessary to adjustthe position ot member 28 so that its retardation by the sleeve 26 willclose valve 24 just as the die contacts with the object in the press orsubstantially atthat time. Figure 8 is an illustration ot'. a form ofpress in which the hydraulic action begins automatically when the dieencounters sufficient resistance from its action on the object in thepress.

In the press shown in Figure 8 the small plunger 40 is a ries of rackteeth extending longitudinally on one side of its outer surface. Ahelical spring 41 inside of the tubular plunger abuts at its upper endagainst a plug 42 which is screw-threaded into the upper end of the boreof the tube. A central opening 43 through plug 42 establishes freepassage for oil between the reservoir 44 and the interior of the tubularplunger. lhe lower end of spring 41 abuts against a head 47 formed onthe upper end of a stem 45 which projects upwardly from the largeplunger 46. The bore of the tubular plunger 40 is restricted at itslower part forming an annular shoulder which coacts with the shoulder onthe lower side of head 47 to limit the movement of small plunger 40 andlarge plunger 46 away from each other. The. plunger member 40 isprovided at its lower end with a packing 48. An axial opening extendsdownward from the top of stem 45 to a point which when the plungers areat the upper limit of their movement is below the lower end of plunger40, and a traverse port 49 extends from the opening 50 to the outer sideof stem 45 at a point just below the lower end of plunger 40 when theparts are in the elevated position mentioned. As in the case of the formof the press shown in Figures 1'to'7 the initial tension of spring 41 inthe press shown in Figure 8 is'sufiicicnt to transmit withoutcompression the force necessary to move the large plunger and diedownward before the die contacts with the object in the press. The addedresistance encountered when the die contacts with the objectin the presscauses the small plunger tubular member with a se- 40 to move downwardrelative to the large plunger 46 with compression of spring 41, thepurpose of spring 41 being to prevent relative movement of the twoplungers before the resistance of the object in the press is encounteredand to permit such relative movement afterwards. While plungers 40 and46 are moving down together they are in the relative position shown inFigure 8, and during this period oil flows through the bore 50 and port49 thus keeping the enlarging space bet-ween the large and smallplungers filled. When the die 51 contacts with and encounters sufiicientresistance from the object in the press the tension of spring 41 is notsuflicien't to resist the force actin between the small and largeplungers, and t 1e small plunger begins to move down relative to thelarge plunger. This has the effect of immediately closing port 49 thusconfining the body of oil between the two plungers and thereafter thepress functions hydraulically. For the return upward movement theoperator rotates the pinion clockwise as viewed in the drawing. Duringthe first part of the up-stroke of the small plunger and until port 49is uncovered the oil between the plungers is confined and the largeplunger moves upward with the small one at a rate inversely proportionalto their areas. Port 49 becomes completely uncovered at the time theshoulder at the bottom of the large bore in the small plunger engagesthe head 47 on the stem 45 projecting upwardly from the large plunger.The press then ceases to act'hydraulically and the force applied to thesmall plunger is transmitted directly to the large plunger and they bothmove upward together at the same rate. This simultaneous and equalupward movement of the two plungers decreases the volume of the spacebetween them and oil flows upward through the port 49 and bore 50 untilthe upper limit of movement is reached, whereupon the mechanism is inposition for a repetition of the cycle above described.

In Figure 9 I show a modified form of valve for controlling the flow ofoil into and out of the space between the plungers. In the modifiedstructure the stem 45 projectmg upward from the large plunger is of lessdiameter than the opening through the end of the small plunger thusleaving an annular space 70 for the passage of oil or the liquld used inthe press. The under side of the head 47 is recessed at71 leaving onlya. peripheral lip 72 to contact with the shoulder 73 at the bottom ofthe large bore in small plunger 40. Openings 74 afl'ord communicationbetween the interior of the small plunger and the space 71 and thencethrough space 70 to the valve 7 5 which controls communication with thespace between the small and large plungers. Valve 75 frictionallyengages stem 45 and remains in the same position relative to stem 45except when moved by the relative movement of the small plunger 40 andstem 45, the latter being fixed to or a part of the large plunger.Assuming that both plungers are in their elevated position and the valve75 lowered from its seat 76, i. e. in open position as shown in Figure9, upon the beginning of the downward movement of small plunger 40'relative to stem 45 valve seat 76 will approach valve 7 5 and close it,this valve closing action being accomplished by a very slight relativemovement of the parts between the mentioned. A packing 77 serves toprevent the passage of oil between valve 75 and stem 45. After theclosing of valve 75 by the action referred .to the press. functionshydraulically until the completion of the power stroke, the operation atthis time being identical with that of the structure shown in Figure 8.Upon the commencement of the return, upward, movement of plunger 40, thevalve 75 remains stationary )y reason of its frictional engagement withstem 45 and valve 75 is therefore opened immediately upon thecommencement of the return, upward, stroke. Depending from the end ofsmall plunger 40 is a cage 78 consisting of several bars having theirlower ends inturned at 79 to underlie the edge of valve 75. After thesmall plunger 40 has moved upward suflicicntly to fully open valve 75the bottom of the cage formed by the parts 79 engages the valve andcarries it upward with plunger 50, leaving the valve open. By means ofthe action described there is free communication between space plungersand the interior of plunger 40 from the moment the return, upward strokecommences, and hence there is substantially no upward movement of thelarge plunger until the shoulder 73 of the small plunger 40 engages thedownwardly projecting rim 72 on the under side of head 47and thereafterthe two plunger-s move together at the same rate. Valve 75 being openthroughout the up-stroke there is a flow of oil downwardly past valve 75while plunger 40 is moving independently of the large plunger and a flowof oil in the opposite directlon at the latter end of the up stroke whenboth plungers are moving upwar ly together at the same rate. In thisrespect the use in the apparatus shown in Figure 8 of the valve shown inFigure 0 results in an operation on the up-stroke similar to that of theapparatus shown in Figure 1-.

The lower end of the large cylinder is closed in both of the pressesillustrated, the end casing 15 in Figure 1 and 52 in Figure 8 serving tocatch the oil that leaks past the large plunger, and the drain pipes 53and 54 respectively carry oft the oil leakage. Packing at 55. best seen1n Figure 8, prevents escape of oil at a point where it would reach thedies and the object in the press.

The press shown in Figure 1 is provided with a hopper 32 to contain thepowdered material used in the dry-mold ceramic process, and the slide 31is provided with a bail 62 whereby the. operator moves it forward andback. The forward movement carries the powder contained in the openingin the slide to the recessed lower die 30 and deposits it thereon. Thetreadle and mechanism connected thereto are the means for ejecting thepressed material from the lower die. The pipes 63 and 54 are steam:onnections for heating the dies.

I claim: e

1. In a device of the class described, relatively small and largecylinders intercomnnmicating and small and large plungers operabletherein, means related to the position of said plungers for governingflow of liquid between said cylinders, a connecting member extending alimited relative movement of said plungers, and resilient means normallyholding said plungers in their most Widely separated position.

2. In a device of the class described, relatively small and largecylinders and small and large plungers operable therein, connectingmembers extending between and permitting a limited relative movement ofsaid plungers, resilient means normally holding said plungers in theirmost widely separated position, means permitting free ingress and egressof liquid to and from the space between said plungers when said plungersare in their most widely separated position and for confining liquidbetween said plungers when said small plunger moves relatively to andtoward said large plunger.

3. In a device of the class described, large and small cylinders andlarge and small plungers operable therein, telescoping membersconnecting said plungers, a spring normall acting to extend saidtelescopic connection, a valve controlling an opening communicating withthe space within said cylinders between said plungers, means formaintaining said valve in open position when said telescopic connectionis fully extended and closed when said telescoping members areapproaching each other.

I; In a device of the class described, large and small cylinders andlarge and small plungers operable therein, telescoping membersconnecting said plungers, a spring 'norbetween and permitting mallyacting to extend said telescoping connection, a valve controlling anopening communicating with the space within said cylinders between saidplungers, means for maintaining said valve in open when said telescopicconnection is fully extended, closed when said telescoping members areapproaching each other and open when said telescoping members arereceding from each other.

5. In a device of the class described, large and small cylinders andlarge and small plungers operable therein, telescoping membersconnecting said plungers, a spring normally acting to extend saidtelescopic connection, said small plunger having a por extendingtherethrough, a valve in said port and opening toward the space betweensaid plungers, a stem connected to said valve, and projecting upwardlytherefrom, a stationary friction member and a coacting friction membermounted on said stem.

6. In a device of the class described, large and small cylinders andlarge and small plungers operable therein, telescoping membersconnecting said plungers, a spring normally acting to extend saidtelescopic connection, a valve controlling an opening communicating withthe space within said cylinders between said plungers, a stationaryfriction member and a co-acting friction member connected to said valve,said triction members being positioned to engage each other after apredetermined amount movement of said plungers in one direction andthereby close said valve, said friction members remaining in engagementduring the remainder of the movement of said plungers in the directionmentioned and operating t open said valve upon reversal of the directionof movement of said plungers.

In testimony whereof, I have subscribed my name.

TIIEODORE C. PROU'IY.

position

